Topic: Client r 474-475 changes

Converted all image files to PNG format, to provide new features like alpha channels and smaller patches.
Improved the look of ship thrust animation, they no longer "look washed out".

Amethyst        T0    Pyr     30
Cisco                T4    Sco    90
Delphi              T1    Eng    21
Neuropath      T0    Tel     10